Never, ever compare a SLI/CF frame rate with a non-SLI/CF frame rate. The two are not comparable. SLI/CF suffers heavily from unsynchronised frames from both cards and in most games, a lot of the frames SLI/CF produces don't increase your viewing experience (don't make the game smoother) but contribute to stuttering. When you're in SLI, what FRAPS shows you as FPS is irrelevant.

It's such a basic concept, and it's so easy to prove it by just taking some frame time benchmarks from FRAPS and so easy to understand what it means; yet nearly all of the major hardware reviewing sites ignore those and say "We had a frame rate increase of 30FPS when we plugged in a second 8800GT!!" Yeah, you did, but it's probably of no use. Hardware sites should inform the consumer about this. No one should buy SLI, 3870x2 or 9800GX2. I own a 8800GT SLI and know this exactly well.

3870x2 didn't take the performance crown from 8800 Ultra, and 9800GX2 didn't take the crown back from 3870x2. Until the new ATI and NVidia single-GPU parts are released, the performance king is still 8800 Ultra.